Dengue virus (DV) infection causes a spectrum of disease ranging from self-limited Dengue Fever to lifethreatening Dengue Hemorrhagic Fever/Dengue Shock Syndrome. The mechanisms of immune protection and pathogenesis are poorly understood, but DV nonstructural protein 1 (NS1) likely plays a key role. NS1 is present in the cytoplasm and on the surface of infected cells and is secreted in a soluble form (sNS1) that circulates in blood, where high sNS1 concentration correlates with increased disease severity. In vitro, sNS1 can activate complement, bind to infected and uninfected cells, and increase viral output from infected hepatoma cells. However, it is unclear if or how sNS1 affects viral dissemination or disease progression in vivo. Similarly, the role of antibodies (Abs) against NS1 is unclear due to the lack of appropriate in vivo models. Anti-NS1 Abs display protective activity against neurovirulent death in mice, but the effects of anti-NS1 Abs on DV infection of more relevant peripheral tissues have never been characterized. Nonetheless, NS1 is included in several DV vaccines under development, including that of our collaborator, Hawaii Biotech, Inc., and no test exists to evaluate the repertoire of Abs generated by either natural infection or vaccination. We have shown that DV infection of interferon receptor-deficient mice reproduces key features of human DV infection, including susceptibility to all four DV serotypes with relevant infection kinetics, appropriate tissue and cellular tropism, sNS1 circulation in the blood, thrombocytopenia correlated with viral load, and fatal vascular leak syndrome. We will use this mouse model to examine the functions of sNS1 and the effects of anti-NS1 Abs on DV infection. We will also use sera obtained from mice, prospective studies of dengue in Nicaragua, and dengue vaccine trials to generate in vitro assays to assess the repertoire of anti-NS1 Abs in infected mice, primary and secondary natural DV infections, and vaccine recipients.
In Specific Aim 1, we will assess the localization and function of sNS1 during DV infection in mice and fatal human dengue cases.
In Specific Aim 2, the effects of anti-NS1 Abs on peripheral DV infection in mice will be evaluated. We will measure the ability of both polyclonal Abs and MAbs against NS1 to protect against DV infection using both NS1 vaccination and MAbs against DV2 NS1, and we will screen for any detrimental in vivo effects of NS1 Abs. Finally, in Specific Aim 3, we will characterize the repertoire of anti-NS1 Abs generated by DV infection and vaccination and will develop in vitro tests to detect anti-NS1 Abs in human serum likely to have protective or pathogenic effects during subsequent DV infection. Together, these results will both elucidate mechanisms of DV pathogenesis and contribute to the development of a safe and effective dengue vaccine.
Although dengue virus (DV) nonstructual protein 1 (NS1) is produced by most vaccines in clinical trials, it is not clear if anti-NS1 Abs contribute to protection or pathogenesis. Also, the function of NS1 in vivo is not well defined. We propose to characterize the cellular targets and functions of sNS1 in vivo, the effect of anti-NS1 Abs on DV infection and pathogenesis, and the repertoire of anti-NS1 Abs elicited by natural DV infection and vaccination in mice and humans. In addition, our mouse model allows questions regarding dengue immunity and pathogenesis, as well as evaluation of candidate therapeutics and vaccines, to be addressed.
|Tsai, Wen-Yang; Youn, Han Ha; Tyson, Jasmine et al. (2018) Use of Urea Wash ELISA to Distinguish Zika and Dengue Virus Infections. Emerg Infect Dis 24:1355-1359|
|Thongsripong, Panpim; Chandler, James Angus; Green, Amy B et al. (2018) Mosquito vector-associated microbiota: Metabarcoding bacteria and eukaryotic symbionts across habitat types in Thailand endemic for dengue and other arthropod-borne diseases. Ecol Evol 8:1352-1368|
|Katzelnick, Leah C; Ben-Shachar, Rotem; Mercado, Juan Carlos et al. (2018) Dynamics and determinants of the force of infection of dengue virus from 1994 to 2015 in Managua, Nicaragua. Proc Natl Acad Sci U S A 115:10762-10767|
|Clemens, Daniel L; Lee, Bai-Yu; Horwitz, Marcus A (2018) The Francisella Type VI Secretion System. Front Cell Infect Microbiol 8:121|
|Huwyler, Camille; Heiniger, Nadja; Chomel, Bruno B et al. (2017) Dynamics of Co-Infection with Bartonella henselae Genotypes I and II in Naturally Infected Cats: Implications for Feline Vaccine Development. Microb Ecol 74:474-484|
|Norris, Michael H; Heacock-Kang, Yun; Zarzycki-Siek, Jan et al. (2017) Burkholderia pseudomallei natural competency and DNA catabolism: Identification and characterization of relevant genes from a constructed fosmid library. PLoS One 12:e0189018|
|Marques, Adriana R; Yang, Xiuli; Smith, Alexis A et al. (2017) Citrate Anticoagulant Improves the Sensitivity of Borreliella (Borrelia) burgdorferi Plasma Culture. J Clin Microbiol 55:3297-3299|
|Nualnoi, Teerapat; Norris, Michael H; Tuanyok, Apichai et al. (2017) Development of Immunoassays for Burkholderia pseudomallei Typical and Atypical Lipopolysaccharide Strain Typing. Am J Trop Med Hyg 96:358-367|
|Parameswaran, Poornima; Wang, Chunling; Trivedi, Surbhi Bharat et al. (2017) Intrahost Selection Pressures Drive Rapid Dengue Virus Microevolution in Acute Human Infections. Cell Host Microbe 22:400-410.e5|
|Bortell, Nikki; Flynn, Claudia; Conti, Bruno et al. (2017) Osteopontin Impacts West Nile virus Pathogenesis and Resistance by Regulating Inflammasome Components and Cell Death in the Central Nervous System at Early Time Points. Mediators Inflamm 2017:7582437|
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